This invention relates to conductive connectors for electrically joining two or more conducting elements, such as a flat connector cable. This invention further relates to such connectors which function to mechanically secure the conducting elements together at the point of junction.
Flat conductor cables have found acceptance in wiring applications wherein conventional round rubber or plastic-coated wires are undesirably visible due to their location and/or the need for a multitude of wiring connections, such as in an office environment. For example, wires which must traverse a room space are variously hidden within the walls, or tacked to baseboards, or placed under the carpeting. Flat conductor cables solve these problems by being locatable under carpeting or tiling without causing objectionable bulging. They accordingly also eliminate the need in many wiring applications for extensive behind-the-wall electrical installation. In new building construction, duct-work is usually built into the walls and floors of the building going up in order to accommoderate conventional wiring. Therefore, if the choice is made to use flat conductor cables instead of conventional wiring, the inconvenience of including the duct-work at the construction stage is eliminated.
Additionally, this type of cable wiring permits renovations of older buildings having conventional wiring to be made with much more ease. Since the cable wiring may be placed beneath carpets, the new work may be performed by simply connecting by means of transition connections cable wiring with the older, more conventional wiring already in place in the building.
As is known, flat conductor cables comprise multiple strips of very thin conductive material, such as copper, separated from each other in a thin insulating sleeve made from a rubber or a plastic material, for example, polyester. Various thicknesses or gauges are known, with the metal strip being generally about as thick as the top and bottom plastic coverings combined, for example, about 6 to 10 mils. A given cable can comprise from several to a large number of metal strips; the width of a given metal strip will vary from cable to cable, and can generally range from about 0.6 to about 1 inch.
Flat conductor cables can and in many cases must be tapped, spliced, or connected to transition junctions or service modules. A transition junction is simply a connection between a portion of a flat conductor cable wiring system and a conventional wiring system. A service module is a box from which power may be tapped from a flat conductor cable wiring system for direct use by the consumer; a common example of which is a simple electrical outlet. Whereas the insulation of round wires is cut and stripped from the wire to achieve these types of connections, flat conductor cables are joined together by clamp connectors with teeth which typically either project all the way through the cable sandwich of plastic-conductor-plastic, and then into the conducting element to which the cable is to be joined, and then to the other side of the clamp, or they are joined by clamp connectors which penetrate just down to the conductive strip of the cable. The openings through which the connectors are fitted are generally produced by pre-punching the cable with a suitable device to produce the proper size opening for the connector. The procedure generally requires special alignment fixtures to insure that the locations of all taps, splices and other connections are correct.
In the current under-carpet wiring installations which are sold commercially, several different types of clamp connectors must be used depending on the type of connection being made; that is, whether the connection is a tap, splice or transition connection. Once the several steps precedent to the installation of the clamp are accomplished, the clamps are secured to the cable with a gripper tool which is manually operated by the installer.
There is therefore a need for a simple procedure for effecting an electrical connection between flat conducting articles such as cables, and another conducting element, which may be another cable, or for example, a service module or transition connection. Where the connection is to be made on the site of the installation, it is highly desirable that this procedure be accomplished quickly, with a minimum amount of equipment, and with equipment which is relatively portable in nature and easy to handle. Further, because of the inherent advantage of the cable structure, it is desirable that the connections conform as much as possible to the flat cable geometry. In other words, the advantages of cable wiring are reduced considerably if taps, splices and other connections result in bulky projections of the wiring system.
It is further more desirable to provide a flat conductor cable installation system which makes use of one type of connector for all of the various types of connections which must be made. It would additionally be advantageous to provide such a system in which the electro-mechanical connection can be made more physically secure through the imposition of greater amounts of force while retaining excellent electrical connection between the conductor strips of the cable and the connector element itself.
Safety considerations require that all flat conductor cable wiring be protected with an outer shield of grounding metal, such as cold-rolled steel. THis shielding is flat and strip like, as is the cable itself, and averages about 10 mils in thickness. When connections of various types are made with the cable itself, the shielding must frequently be spliced and redirected to follow the operations being performed on the flat conductor cable. It would thus be of further advantage to be able to use the connection arrangement and procedure for flat conductor cables to connect various strips of shielding as well. Since the shielding is electrically conductive, such connections would also have to be electro-mechanical and secure in nature.